|The Prevention and Control of Iodine Deficiency Disorders - Nutrition policy discussion paper No. 3 (UNSSCN, 1988, 130 p.)|
|3. PREVALENCE OF IODINE DEFICIENCY DISORDERS (IDD)|
In the 1960 WHO monograph, Kelly and Snedden estimated a population of 200 million in the world to be suffering from goitre (Clements et al., 1960 p.28). More recent estimates exceed this figure in spite of extensive iodization programmes. The worldwide distribution of Iodine Deficiency Disorders (IDD) in developing countries is shown in Fig. 1 in "Introduction and Policy Implications" Section.
There is consensus that some 800 million people are at risk of IDD from living in iodine-deficient environments, with 190 million suffering from goitre and more than 3 million with overt cretinism, while millions more suffer from some intellectual deficit (Hetzel, 1987 p.7).
In the Southeast Asia Region eight countries - Bangladesh, Bhutan, Burma, India, Indonesia, Nepal, Sri Lanka and Thailand - all have significant IDD problems. Altogether in these eight countries, it has been estimated in the light of extensive surveys that 277 million are at risk of IDD, some 102 million have goitre, 1.5 million are cretins, and many more suffer from some degree of mental or motor impairment as a result of iodine deficiency (Clugston and Bagchi, 1985).
In the People's Republic of China, it has been estimated that some 300 million are living in iodine-deficient regions and therefore exposed to the risk of IDD. Only one-third of this population was reported as adequately covered by control programmes in 1982 (Ma et al., 1982)1. Fever data are available from Africa, but the indications are that the IDD problem is widespread (see Section 3.3). In Latin America the problem persists in Bolivia, Peru, Ecuador and many other countries, in spite of attempts to control IDD with iodized salt (WHO, 1984). IDD persist in many European countries including Germany (both F.R.G. and G.D.R.), Romania, Poland, Spain, Portugal and Italy (European Thyroid Association, 1985).
1More recent information (Ma and Li, 1987) indicates coverage expanding to 87% of the deficient population.
Detailed information from the major regions follows. Individual country programmes are considered in Section 6.